Aqueous resin crosslinking agent, aqueous resin crosslinking agent-containing liquid, and aqueous resin composition

Abstract

A waterborne resin crosslinking agent containing a predetermined polycarbodiimide compound (A) having an oxyalkylene group, a predetermined polycarbodiimide compound (B), and a surfactant (C), each polycarbodiimide compound has a structure in which an isocyanate group is capped with a predetermined end-capping compound at each of both terminals, a total content of the oxyalkylene group in (A) is 15% by mass or more, a total content of the oxyalkylene group in (A) and (B) based on a total amount of (A) and (B) is 10% by mass or less, and a content of (C) is 0.1 to 20 parts by mass based on a total content of (A) and (B) of 100 parts by mass.

The invention claimed is: 
     
       1. A waterborne resin crosslinking agent comprising at least one polycarbodiimide compound (A) selected from the group consisting of a polycarbodiimide compound (A1) and a polycarbodiimide compound (A2), a polycarbodiimide compound (B), and a surfactant (C), wherein the polycarbodiimide compound (A1) has a structure in which an isocyanate group is capped with an end-capping compound (T1) represented by the following general formula (1) at each one of a first and a second terminal of the polycarbodiimide compound (A1),
 the polycarbodiimide compound (A2) has a structure in which an isocyanate group is capped with the end-capping compound (T1) at a first terminal of the polycarbodiimide compound (A2), and has a structure in which an isocyanate group is capped with an end-capping compound (T2) at a second terminal of the polycarbodiimide compound (A2), 
 the polycarbodiimide compound (B) has a structure in which an isocyanate group is capped with an end-capping compound (T3) at a first terminal of the polycarbodiimide compound (B), and has a structure in which an isocyanate group is end-capped with an end-capping compound (T4) at a second terminal of the polycarbodiimide compound (B):
   R 1 (OCHR 2 CH 2 ) n OH  (1)
 
 
 wherein R 1  is an alkyl group having 1 to 4 carbon atoms; R 2  is a hydrogen atom or a methyl group; n is an integer of 7 to 30; and the end-capping compound (T1) capping the first terminal of the polycarbodiimide compound (A1) and the end-capping compound (T1) capping the second terminal thereof, and the end-capping compound (T1) capping the first terminal of the polycarbodiimide compound (A2) may be the same or different from each other, 
 the end-capping compounds (T2), (T3), and (T4) are each independently a compound having one amino group, isocyanate group, epoxy group, or carboxy group, or a compound having one hydroxyl group other than the end-capping compound (T1), 
 a total content of an oxyalkylene group (OCHR 2 CH 2 ) in the polycarbodiimide compound (A) is 15% by mass or more, 
 a total content of an oxyalkylene group in the polycarbodiimide compounds (A) and (B) based on a total amount of the polycarbodiimide compounds (A) and (B) is 0.3 to 1.2% by mass, 
 a content of the surfactant (C) is 0.1 to 20 parts by mass based on a total content of the polycarbodiimide compounds (A) and (B) of 100 parts by mass, and 
 a content of the polycarbodiimide (A) is 1 to 3 parts by mass based on a total content of the polycarbodiimide compounds (A) and (B) of 100 parts by mass. 
 
     
     
       2. The waterborne resin crosslinking agent according to  claim 1 , wherein the polycarbodiimide compound (A) is the polycarbodiimide compound (A1). 
     
     
       3. The waterborne resin crosslinking agent according to  claim 1 , wherein the polycarbodiimide compound (A) is a mixture of the polycarbodiimide compound (A1) and the polycarbodiimide compound (A2). 
     
     
       4. The waterborne resin crosslinking agent according to  claim 1 , wherein the end-capping compound (T1) capping one terminal of the polycarbodiimide compound (A1) and the end-capping compound (T1) capping the other terminal thereof are the same. 
     
     
       5. The waterborne resin crosslinking agent according to  claim 1 , wherein the end-capping compounds (T3) and (T4) are the same. 
     
     
       6. The waterborne resin crosslinking agent according to  claim 1 , wherein the end-capping compound (T1) is polyethylene glycol monomethyl ether. 
     
     
       7. The waterborne resin crosslinking agent according to  claim 1 , wherein the surfactant (C) is one or more selected from the group consisting of an anionic surfactant and a nonionic surfactant. 
     
     
       8. A waterborne resin crosslinking agent-containing liquid comprising the waterborne resin crosslinking agent according to  claim 1  and an aqueous medium. 
     
     
       9. The waterborne resin crosslinking agent-containing liquid according to  claim 8 , wherein the aqueous medium is water or a mixed solvent of water and a hydrophilic solvent. 
     
     
       10. A waterborne resin composition comprising the waterborne resin crosslinking agent and a waterborne resin,
 the waterborne resin crosslinking agent comprising at least one polycarbodiimide compound (A) selected from the group consisting of a polycarbodiimide compound (A1) and a polycarbodiimide compound (A2), a polycarbodiimide compound (B), and a surfactant (C), wherein the polycarbodiimide compound (A1) has a structure in which an isocyanate group is capped with an end-capping compound (T1) represented by the following general formula (1) at each one of a first and a second terminal of the polycarbodiimide compound (A1), 
 the polycarbodiimide compound (A2) has a structure in which an isocyanate group is capped with the end-capping compound (T1) at a first terminal of the polycarbodiimide compound (A2), and has a structure in which an isocyanate group is capped with an end-capping compound (T2) at a second terminal of the polycarbodiimide compound (A2), 
 the polycarbodiimide compound (B) has a structure in which an isocyanate group is capped with an end-capping compound (T3) at a first terminal of the polycarbodiimide compound (B), and has a structure in which an isocyanate group is end-capped with an end-capping compound (T4) at a second terminal of the polycarbodiimide compound (B):
   R 1 (OCHR 2 CH 2 ) n OH  (1)
 
 
 wherein R 1  is an alkyl group having 1 to 4 carbon atoms; R 2  is a hydrogen atom or a methyl group; n is an integer of 7 to 30; and the end-capping compound (T1) capping the first terminal of the polycarbodiimide compound (A1) and the end-capping compound (T1) capping the second terminal thereof, and the end-capping compound (T1) capping the first terminal of the polycarbodiimide compound (A2) may be the same or different from each other, 
 the end-capping compounds (T2), (T3), and (T4) are each independently a compound having one amino group, isocyanate group, epoxy group, or carboxy group, or a compound having one hydroxyl group other than the end-capping compound (T1), 
 a total content of an oxyalkylene group (OCHR 2 CH 2 ) in the polycarbodiimide compound (A) is 15% by mass or more, 
 a total content of an oxyalkylene group in the polycarbodiimide compounds (A) and (B) based on a total amount of the polycarbodiimide compounds (A) and (B) is 0.3 to 1.2% by mass, 
 a content of the surfactant (C) is 0.1 to 20 parts by mass based on a total content of the polycarbodiimide compounds (A) and (B) of 100 parts by mass, and 
 a content of the polycarbodiimide (A) is 1 to 3 parts by mass based on a total content of the polycarbodiimide compounds (A) and (B) of 100 parts by mass. 
 
     
     
       11. The waterborne resin composition according to  claim 10 , wherein the waterborne resin has a group selected from the group consisting of a carboxy group, an amino group, and a hydroxyl group. 
     
     
       12. The waterborne resin composition according to  claim 10 , wherein the waterborne resin is one or more selected from the group consisting of a polyester resin, an acrylic resin, a polyurethane resin, an epoxy resin, a styrene-acrylic resin, a melamine resin, a polyolefin resin, and a fluororesin. 
     
     
       13. The waterborne resin composition according to  claim 10 , wherein the waterborne resin composition is an adhesive composition, a fiber treatment agent composition, a coating agent composition, or a paint composition. 
     
     
       14. The waterborne resin composition according to  claim 13 , wherein the paint composition is wet-on-wet coating composition. 
     
     
       15. A resin film formed from the waterborne resin composition according to  claim 10 . 
     
     
       16. An article obtained by forming the resin film according to  claim 15  on a base material.